Means for drying corrugated board



Patented Aug. 12, 1941 William R. Swanson, Toronto, Ontario, andi-Peter Rintoul, Fairbank, Ontario, Canada, assignors' to Gair Company CanadaY Limited,

Ontario, Canada Toronto, l

Application March `20, 1939, Serial No. `.262,944

6 Claims. (CLM-gico) The principal objects of this invention are to effect the rapid de-hydration of corrugated board during the process of manufacture thereof and to provide a form `of mechanism which Will'automatically accommodate strips of various widths of board and which will require the minimum of attention.

The principal features of the invention reside in the novel form of apparatus for carrying the invention into effect whereby the corrugated strip is advanced through a drying zone or zones in which the respective edges are subjected to high and low air pressures to cause a denite travel of heated air longitudinally of the corrugations to eilect the maximum moisture extraction in the minimum of time.

A further and important feature resides in the novel manner of forming enclosed pressure areas about the respective edges of the strip as it is being advanced.

Still further features of importance consist in the novel construction of a bed over which the corrugated board is passed whereby said bed is provided with perforated areas on leither side communicating with air ducts arranged therebeneath, and whereby exible means is provided to cover the corrugated .board and extend beyond the edges thereof and to contact with the corrugated surface to form ducts connecting the perforations of said bed with the corrugations 'of the board.

In the drawing Figure 1 is a fragmentary side elevational view rof. an apparatus suitable for carrying this invention into effect.

Figure 2 is a fragmentary plan view of one side drying rooms Where the finished board is required to stand for some period in order to effect nal drying thereof.

` The present invention has been devised to overcome these difliculties in a simple but eii'cient manner, and inthe form of the invention'shown framemembers l` and 2 are spaced'apart to support a flat table section 3 Vwhich may be of sheet metal and this is dished downwardly at opposite sides to form suction andpressure chambers l and 5 respectively, which chambers are arranged in pairedfrelation and extend fromiadjacent the outer vedge portions'to the intermediate'portion of the table section 3. Y

'A lat sheet'or' panel of metal 6, presenting a smooth'upper' surface over which the corrugated board to be dried is adapted tofslide, is placed overthe `table section 3 and thev portions overlying the suction 'andairfch'ambers' 4 and' 5 are perforated asfshwn at'fl and 8 respectively. One,

two or morepairs ofthe chambers Il and 5 may of the apparatus broken away in part to show a i corrugated strip passing over one of the perforated suction Zones,

Figure 3 is a transverse sectional elevation taken on the line 3-3 of Figure 2.

Figure 4 is an enlarged fragment-ary `view through vone of the perforated pressure zones showing the corrugated board and overlying travelling belt. n

Figures 5,and 6 are diagrammatic part structural views taken transversely of the drying table .but also in order to provide storage;4 spacein 5 the Conduitl I 0' be provided in progression, and a conduit 9 for supplyingheated airha's 'a tubular lconnection with each pocket `5, while a suction conduit It has a tubular connection with each pocket 4 and air is heated Ain 'any suitable manner and circulatedunder 'force by' a suitable blower (not shown)v` having the pressure outlet connected with the conduit '9'by the conduit, 9"and the suction inlet connected withthe conduit l0 by "Optionally the conduit `9 maybe connected with the'pressure outlet of 'one blower to direct highly heated airy" to -the chamber ilA Whilela separate blower may be "provided having its suction side connected with the conduit l and discharged to atmosphere. j y l .The'corrugated'board Ll as it comes fromvthe formingfand glueing machine advances over the upperH perforated" panel 5 withthe corrugations xtendingf'transversely thereof so that one edge registersl with the Vpressure chamber or chambers 5 whilefthe"other` dge registers withthe suction chamber or chambersV fl.' v j f `A comparativelyr heavy belt or mat I2 of endless formation'sso mounted and driven that its lower stretch frestsonA the corrugated board and by frictional engagement therewith causes the latter to move overthe panel 6, the board easily sliding over the` smooth".surfaceV 'ofthe latter.

' Such belt'is'of 'substantially greater width than the'strip of 'cardboard' so that the overhanging 1edge portion 12?.. thereof will drop 'downwardly and contact with theQmarg'inal portions of the uppergtable panelt at the outward side ofthe panel 6 and such rollers are here shown provided,

with flanges I which bear on the edge extremities of the belt to hold the same lclosely to the It will be appreciated that the construction shown provides for the accommodation of various widths of strips which may be passed therethrough for drying purposes and the same belt I2 will co-operate with the various widths of strips to form the sealing pockets I3 and I4 at the edges thereof.

What we claim as our invention is:

1. Apparatus for drying corrugated board comprising a table surface over which the board to be dried is advanced in a direction transversely panel 6. The rollers I4 are suitablyguided and rotatably mounted in carrying brackets I6.. n i

With the arrangement shown it will be. apparent that when highly heated air under pressure is forced into the chamber 5 it will pass out through the perforations 8,'which are located beyond the edge of the corrugated strip to be dried, and on entering the enclosure or pocket I3 it will be causedto flow through'the transverse spaces Vbetween the corrugations in extensive surl face contact with the corrugated'board so that the board will be rapidly dehydrated and the adhesive firmly set,

Simultaneous with the application of heated air pressureto the'chamber 5 the 'suction Within the chamber 4 will assist in accelerating the ilow of4 heated air' through the 'corrugatio'ns which, on reaching thepocketor enclosure I4, will pass down through the' exposedopenings 'I into the loiamberl'o4 and finally Out through the' conduits and It may be desirable in certain'cases at least to provide ansuction and pressure pocket such 'as 4 andV 5 at `each side of the drying table so that theheated air will be caused to flow'rst from one `side of the corrugated board tothe 'other in passing over one set 'of pockets and' then from the saidother sidel to the first-mentioned side in subsequently passing overa second set `of pock ets in order to achieve a more balanced drying of the product and in Figures 5and 6 we have shown a suitable arrangementfor this purpose.

Figures 5-and6represent two drying zones spaced apart in a direction longitudinally of the direction of travel'of the belt I2, the pockets 4' representingY suctionl or outlet chambers having outlets I0", while the pockets 5' represent pressure chambers locatedat opposite sides'of the perforated table or plate 6 in offsetrelation to whichthe dry heated airis directed under'pressure through the ducts 9"; each chamber '4 being arranged transversely opposite to a pres-l sure chamber 5 as shown.

With this arrangement it will be apparent that any tendency to dry one side of the'board more than the other with 'a consequent tendency" to warp the product will be avoided due to the bal-Y anced application of the drying air4 flows. an -arrangement is particularly advantageous where the board strip is exceptionally wide.l

Further structural variations'may be resorted to within the essential spirit of the invention and while the present invention has been devised particularly in connection with the drying ofcorrugated boards, it is readily adaptable `to the handling'of other types of board products, and

in the case of a non-'corrugated product the rollers I4 may be such as to substantially clear the belt I2V intermediate of its width so'that the pressure of the forced blast will substantially raise the board strip sufliciently to allow the air flow to pass between the panel 6 and board strip and/or between the board strip and belt I2.

Such i of the corrugations, said table surface having perforated areas extending beyond the side edges of thevboard, said table having sealing areas at vthe outward sides of the perforated areas, a ilexible drive belt engaging the upper surface of the corrugated board in driving contact and having 'edge portions extending beyond the edges of the board over said perforated areas and having substantial sealing engagement with said sealing areasand forming with the board and table surface pressure and suction chambers respectively at the ends of the corrugations, the perforations inthe table surface forming inlet and outlet passages'for said pressure and suction chambers, means directing heated air to said inlet perforations from below said table surface, and means for conducting air from said outlet perforations below saidl table surface.

2. Apparatus as claimed in claim 1 in which said sealing Vareas at the outward side of the perforated 'areas comprise surfaces disposed below the Vupper level of the board with which the extending edge portions of the flexible belt are adapted to engage by downward flein'ng, means being provided for holding said belt edges in downwardly ilexed sealing relation to'said sealing areas.

V3.-Apparatus `as claimed in claim 1 in which said sealing areas at the outward side of the perforated areas comprises surfaces disposedI below the upper level of the board with which the extendingedge portions of the flexible belt are adapted to engage by downward flexing, means being provided for weighting said belt including roller means extending below the upper surface of the intermediate portion of the belt and engaging the belt edges to hold the same in downwardly'flexed sealing relation to the said sealing areas.

4. Apparatus as claimed in claim 1 in which said sealing areas at the outward side of the perforated areas comprise surfaces disposed below the upper level of the board with which the extending edge portions of the exible lbelt are adapted' to engage by downward flexing, and rollersextending transversely of said belt and resting on the intermediate portion thereof to weight the same downwardly on the board, said rollers having portions of greater diameter at the ends engaging the edge portions of the belt to hold the same in downwardly flexed sealing relation to the said sealing areas.

5. Apparatus for drying corrugated board and the like comprising a table having perforated areas at respective sides, pressure and suction chambers on' the underside of the table one communicating' withV the perforated area of one side of the table and the other communicating with the perforated area of the other side of the table, and means for overlapping said perforated areas at Vopposite sides of a board overlying said table and forming Vwith the board and with said table pressure andsuction enclosures communicating with said respective chambers by way of the respected perforated zones, said overlapping means including a conveying belt engaging in frictional driving contact with said board to advance the same over said table past the perforated zones..

6. Apparatus for drying corrugated board comprising atable surface over which the board to be dried is advanced in a direction transversely of the corrugatons, said table surface having perforated areas extending beyond the side edges of the board, conveying belt means co-operatively engaging said board and overhanging the edges thereof for substantial sealing engagement with said surface beyond the perforations therein and forming with said board and surface pres- WILLIAM R. SWAN SON. PETER RINTOUL. 

